CN 103301805 A discloses a carbon dioxide adsorbent, which is prepared by mixing a molecular sieve with a solution containing two or three salts of alkaline cations (i.e., sodium ions, potassium ions and calcium ions), and subsequently by washing and drying the sieve. The suitable salt of sodium ions may be sodium chloride, sodium nitrate, sodium sulfate, sodium hydroxide, sodium carbonate, sodium bicarbonate, sodium acetate or sodium phosphate. The suitable salt of potassium ions may be potassium chloride, potassium nitrate, potassium sulfate, potassium hydroxide, potassium carbonate, potassium bicarbonate, potassium acetate or potassium phosphate. The suitable salt of calcium ions may be calcium chloride or calcium nitrate.
However, during the preparation of such conventional carbon dioxide adsorbent, it is time-consuming to deliver the alkaline cations into pores of the molecular sieve. Moreover, in use, it takes a long time for the carbon dioxide gas to diffuse into the molecular sieve and react with the aforesaid alkaline cations, and a solid product resulting from the reaction of the alkaline cations with carbon dioxide precipitates and blocks the sieve, rendering the same hardly reusable.
Therefore, the applicants have endeavored to develop a novel and convenient method to effectively collect carbon dioxide.